Or, you guys just haven't learned yet that those are the two characters you'll be using in Co-Op.
Theory about the core-bot:You know that sweet cutscene at the end of Portal where your camera flies to cake and suddenly red spots appear in the background? Those are cores without personalities, because they're not restricted by personality, they can do whatever they want. Apparently, a core decided to grow gigantic loving arms and grow a portal gun too.
If you listened to the portal 2 podcast, there will be one of those things that you have to fight. Cave Johnson uploaded his brain into a morality core, and put legs on it.
Obama approves of Portal.
No clue if it's shopped. Might be. I just found it when googling portal...
Source: http://kokugamer.com/2010/03/20/obama-cant-wait-for-portal-2/
Maybe that pic was shopped also